The present invention relates to marking devices in general and, more particularly, to a marking device for semiconductor wafer dies.
Various types of marking devices or "inkers" are used in the semiconductor industry to provide intermittent or continuous marks on semiconductor dies. Conventional inkers utilize a filament or fishline to transfer the marking fluid or ink to the semiconductor die by physically contacting the die. The action of the filament deposits the ink on the die at the time of contact between the filament and the die. The conventional inkers normally require maintenance at least every couple of hours and are susceptible to clogging with dried ink. Furthermore, in order to change the ink dot size with the conventional inkers, the filament itself must be changed. The disadvantages severely impair the usefulness of conventional "inkers" in high speed semiconductor production operations.
It is accordingly a general object of the present invention to provide an improved marking device or "inker" for semiconductor wafers.
It is a specific object of the present invention to provide a non-contacting, non-clogging inker for marking semiconductor wafer dies that eliminate the shortcomings of the prior art inkers.
It is still another object of the present invention to provide a semiconductor wafer die inker having a sufficient reservoir capacity to permit extended periods of operation between routine maintenance procedures.
It is a feature of the present invention that while the ink reservoir is maintained at ambient pressure, evaporation of the ink is minimized.
It is still another feature of the present invention that ink splatter is minimized through the use of a specific energerzation cycle for the inker solenoid.